Rapid AED Withdrawal During vEEG Monitoring May Be Safe and Effective
Discontinuation of antiepileptic drug (AED) therapy during concurrent video and EEG monitoring (vEEG) may be safe for patients with epilepsy, according to research presented at the 67th Annual Meeting of the American Epilepsy Society.
To determine the safety and long-term effects of AED withdrawal or discontinuation during this diagnostic procedure, investigators at the University of Saskatchewan in Saskatoon, Canada, conducted a prospective study of 150 patients with epilepsy admitted to their vEEG telemetry unit over a period of five years. Neurologists discontinued the patients’ medication therapy according to a standardized rapid AED withdrawal protocol. Rapid discontinuation was not performed for patients with a history of status epilepticus or phenobarbital exposure. The researchers then assessed the number of patients who had subsequent seizures, the safety of the withdrawal and telemetry procedures, and epilepsy surgery outcomes.
The group recorded seizures and nonepileptic events in 84.8% of the patients. This diagnostic yield was achieved over a mean monitoring duration of 4.53 days. The researchers found no benefit of longer monitoring. Habitual seizures were recorded in 107 patients to support a diagnosis of epilepsy. The investigators recorded nonepileptic events in 36 patients. The vEEG findings changed patient management for 93% of the cohort and likely improved quality of life by decreasing AED consumption and reducing seizure frequency.
Overall, 34% of the patients received epilepsy surgery. The probability of a good outcome (ie, Engel Class I or II) at 24 months was 78% among patients who underwent surgery and 40% among patients who did not. The overall complication rate of the surgery was 5.3%, and the most common complication was musculoskeletal pain secondary to clinical seizure activity. The investigators observed no mortality following surgery. In the first month following monitoring, 2.5% of patients were admitted to an emergency room for seizure clustering.
“VEEG telemetry monitoring with early cessation of AED therapy is safe and effective,” said Syed A. Rizvi, MD, a neurology resident at the University of Saskatchewan and lead author of the report. “Surgical outcomes are favorable and support the use of this technique under the supervision of a team comprising epileptologists, nurses, and EEG technologists.”
Prolonged Seizures During Childhood May Not Necessarily Damage the Brain
Childhood convulsive status epilepticus (CSE) may not damage the hippocampus unless it occurs years after the causative event, according to a study presented at the 67th Annual Meeting of the American Epilepsy Society. Prolonged febrile seizures also may not impair hippocampal growth in children.
Neurologists have long hypothesized that prolonged febrile seizures, the most common form of childhood CSE, cause mesial temporal sclerosis (MTS), which entails a loss of neurons and scarring of the hippocampus. Whether prolonged convulsions lead to long-term damage to the hippocampus or to MTS is uncertain.
A team of investigators from the United Kingdom and the United States used three-dimensional MRI imaging to measure hippocampal volume in 144 children. The cohort included 74 patients with seizures classified into four subgroups: prolonged febrile seizure, acute symptomatic (CSE at time of causative event such as meningitis or head injury), remote symptomatic (CSE months to years after causative event), and idiopathic or unclassified. The cohort also included 70 healthy controls.
Each hippocampal slice was measured independently by two investigators blind to clinical details. The hippocampal volume was measured on each side, and right–left asymmetry was calculated using asymmetry index. Volumetric images were taken at a mean follow up of 8.5 years (range 6.3 to 10 years) after the convulsive episode. The investigators also compared these measures across all patient groups.
The researchers found no significant corrected volumetric differences between the groups, except for the subgroup of children with remote symptomatic CSE, whose mean corrected hippocampal volume was 553 mm3 lower than that of controls. Asymmetry of the hippocampal structure also was significantly greater in the remote symptomatic subgroup, compared with the other groups. The investigators found no significant differences in asymmetry or corrected volume between the other CSE groups and healthy controls.
“On group analysis, hippocampal growth in children who had prolonged febrile seizures, acute symptomatic, and idiopathic or unclassified CSE was not impaired at a mean follow-up of 8.5 years post CSE,” said Suresh Pujar, MD, clinical research fellow in epilepsy at the Institute of Child Health, University College of London, and lead author of the study. “But children with remote symptomatic CSE have a significant reduction in hippocampal volume and increased asymmetry, compared with all the other groups in our study.”
The results of the study suggest that prolonged seizures, whether febrile or afebrile, may not have a lasting effect on hippocampal growth in children who were neurologically normal before CSE, according to the investigators.